Cam Rotation and Timing?

[thenuge15]

I was wondering if somebody can please explain to me what cam rotation and timing are? Also what affect these, and what problems can the cause? Will twisting the string a couple times to shorten draw-length affect this? Thanks-Sam

[Straightarrow]

This will depend on the type of cam on the bow. What cam are you shooting?

[JeffB]

yeah..more details plaase as it's a pretty lengthy subject..timing/cam rotation, synch, etc.

Cam Rotation and timing are basically the same thing and affect all types of cams

Cam Synch applies to dual cams & to a much lesser extent hybrid cams.

[thenuge15]

Well I was just wondering in general what can cause this, and what it does. I will be getting a new outback soon so the shop should set it up correctly. I was asking more out of curiosity than specifically about my bow. It seems like twisting the stiring would bring the cam back a little, and then it would almost constantly me like a drawn a very minute amount.

[Ate-Up]

When you get the new outback you might consider replacing the tiger twist string with a low strech custom string. That way once you shoot in the string you wont have to worry about the cam timing.Winnerschoice and Berry strings are both good choices,and if your really interested i know a guy that can hook you up with a set for $50. He can have your string/cable to you in less than a week.

[Bigpapascout]

the wheels (or cams) of a two-wheeled compound rotate as you draw the bow. Since their axles are not in the centre, their rotation, in effect, changes the length of the bow. This, combined with the relationship between the large diameter of the string side and the smaller diameter of the cable side of the cam is what gives the compound its familiar peak weight and let-off. There is no need to go into the details, but it is important to understand that if the wheels are not rotating in unison, they are exerting different pressures on the cables, and allowing the limbs to move at different speeds. The end result is complex. Slow motion photography shows that the wheel that starts early does not necessarily reach the end of its stroke first, but at various times may be in the lead, or may be following. This can cause the arrow nock to rise and fall unpredictably during the power stroke, and give a substantial up and down movement at launch. In addition the double impact of the limbs arriving one after the other does nothing to improve accuracy or limit damaging vibration!

Finally, if the wheels are not timed in unison, you are likely to find problems at full-draw, particularly if you shoot off the wall or stops. One wheel will be solidly at the end of its draw, while the other will still be able to move. The end result is likely to be an unstable, rocking movement hardly conducive to a good aim (this is what is meant by the cams 'fighting each other').

[thenuge15]

So I understand the mathews have holes in there cam and the string is suppose to be between them. If I check this periodically it should be fine? What about twisting the string?

[JeffB]

ORIGINAL: thenuge15

So I understand the mathews have holes in there cam and the string is suppose to be between them. If I check this periodically it should be fine? What about twisting the string?

Actually on the Mathews cams when you run a straightedge through the center of those holes, the string should be directly parallel to the straightedge.

Buy yourself a high quality aftermarket string and cable..something like Winners Choice, VaporTrail, Stone Mountain, etc...and likely you will only have to put a twist or two at most in your buss cable after the harness/string settles.

[Bigpapascout]

best way to ensure that your string and harnesses are not creeping is to mark the cam in line with the limb check the poundage and record it for future reference
if you ever feel that the poundage and draw length has changed
you can check the poundage.if your draw weight has gone up the string has stretched, if the weight goes down your power harness has stretched
to remedy the problem simply press the bow and twist the string or harness (which ever has stretched) until it is back where it belongs.

this pertains to solo cam bows only

[BTM]

Sure is nice to see that some folks know the difference between timing and synchronization. Too bad most of the magazine writers don't; they almost always use the terms interchangeably!